Francesca Pistoia

Migraine and Hemorrhagic Stroke A Meta-analysis

Background and Purpose— Several studies have assessed the possible increased risk of hemorrhagic stroke in migraineurs, drawing differing conclusions. No meta-analysis on the topic has been published to date. Methods— Multiple electronic databases (MEDLINE, EMBASE, Science Citation Index, and the Cochrane Library) were systematically searched up to March 2013 for studies dealing with migraine and hemorrhagic stroke. We selected case–control and cohort studies with a clear definition of the diagnostic criteria for migraine and hemorrhagic stroke, using an adjusted model or a matching procedure that could control for potential confounders, and reporting effect estimates with 95% confidence intervals (CIs) or enough data to allow calculation of those numbers. Adjusted odds ratios and hazard ratios were used to estimate effect size. Results— Of 11 264 records, we identified 8 studies (4 case–control and 4 cohort studies) involving a total of 1600 hemorrhagic strokes, which were included in the meta-analysis. The overall pooled adjusted effect estimate of hemorrhagic stroke in subjects with any migraine versus control subjects was 1.48 (95% CI, 1.16–1.88; P=0.002), with moderate statistical heterogeneity (I2=54.7%; P value for Q test=0.031). The risk of hemorrhagic stroke in subjects with migraine with aura (1.62; 95% CI, 0.87–3.03; P=0.129) was not significant. Compared with control subjects, the risk of hemorrhagic stroke was greater in females with any migraine (1.55; 95% CI, 1.16–2.07; P=0.003) and in female migraineurs aged less than 45 years (1.57; 95% CI, 1.10–2.24; P=0.012). Conclusions— Available studies suggest that subjects with migraine have an increased risk of hemorrhagic stroke. Further studies are needed to address the hemorrhagic stroke risk according to migraine type, age, sex, and hemorrhagic stroke type.

Cortical sources of resting-state alpha rhythms are abnormal in persistent vegetative state patients.

OBJECTIVE High power of pre-stimulus cortical alpha rhythms (about 8-12 Hz) underlies conscious perception in normal subjects. Here we tested the hypothesis that these rhythms are abnormal in persistent vegetative state (PVS) patients, who are awake but not aware of self and environment. METHODS Clinical and resting-state, eyes-closed electroencephalographic (EEG) data were taken from a clinical archive. These data were recorded in 50 PVS subjects (level of cognitive functioning--LCF score: I-II) and in 30 cognitively normal subjects. Rhythms of interest were delta (2-4 Hz), theta (4-8 Hz), alpha 1 (8-10.5 Hz), alpha 2 (10.5-13 Hz), beta 1 (13-20 Hz), and beta 2 (20-30 Hz). Cortical sources were estimated by low-resolution electromagnetic tomography (LORETA). Based on LCF score at 3-months follow-up, PVS patients were retrospectively divided into three groups: 30 subjects who did not recover (NON-REC patients; follow-up LCF: I-II), 8 subjects classified as minimally conscious state patients (MCS patients; follow-up LCF: III-IV), and 12 subjects who recovered (REC patients; follow-up LCF: V-VIII). RESULTS Occipital source power of alpha 1 and alpha 2 was high in normal subjects, low in REC patients, and practically null in NON-REC patients. A Cox regression analysis showed that the power of alpha source predicted the rate of the follow up recovery, namely the higher its power, the higher the chance to recover consciousness. Furthermore, the MCS patients showed intermediate values of occipital alpha source power between REC and NON-REC patients. CONCLUSIONS These results suggest that cortical sources of alpha rhythms are related to the chance of recovery at a 3-months follow-up in patients in persistent vegetative state. SIGNIFICANCE Cortical sources of resting alpha rhythms might predict recovery in PVS patients.

Degenerative disorders of the spine

Patients with back pain and degenerative disorders of the spine have a significant impact on health care costs. Some authors estimate that up to 80% of all adults experience back pain at some point in their lives. Disk herniation represents one of the most frequent causes. Nevertheless, other degenerative diseases have to be considered. In this paper, pathology and imaging of degenerative spine diseases will be discussed, starting from pathophysiology of normal age-related changes of the intervertebral disk and vertebral body.

Awakenings and awareness recovery in disorders of consciousness: is there a role for drugs?

Disorders of consciousness (DOC) include coma, vegetative state (VS) and minimally conscious state (MCS). Coma is a condition of unarousability with a complete absence of wakefulness and awareness, whereas VS is characterized by a lack of awareness despite a preserved wakefulness. Patients in coma are unconscious because they lack both wakefulness and awareness. Patients in a VS are unconscious because, although they are wakeful, they lack awareness. Patients in a MCS show minimal but definite behavioural evidence of self and environmental awareness.Coma results from diffuse bilateral hemispheric lesions or selective damage to the ascending reticular system (which is functionally connected to the cerebral cortex by intralaminar thalamic nuclei). VS is a syndrome that is considered to be the result of a disconnection of different cortical networks rather than a dysfunction of a single area or a global reduction in cortical metabolism. As revealed by functional imaging studies, clinical recovery is often associated with a functional restoration of cortico-thalamo-cortical connections. Depending on the amount of network restored, patients may regain full consciousness or remain in a MCS. Molecular and neural mediators may indirectly contribute to the above restoration processes owing to their role in the phenomenon of neural synaptic plasticity. Therefore, there is growing interest in the possible effects of drugs that act at the level of the CNS in promoting emergence from DOC.Sporadic cases of dramatic recovery from DOC after the administration of various pharmacological agents, such as baclofen, zolpidem and amantadine, have been recently supported by intriguing scientific observations. Analysis of the reported cases of recovery, with particular attention paid to the condition of the patients and to the association of their improvement with the start of drug administration, suggests that these treatments might have promoted the clinical improvement of some patients. These drugs are from various and diverging classes, but can be grouped into two main categories, CNS stimulants and CNS depressants. Some of these treatments seem to directly encourage a consciousness restoration, while others play a more determinant role in improving cognitive domains, especially in patients with residual cognitive impairment, than in the field of consciousness.Given the great interest recently generated in the scientific community by the increasing number of papers addressing this issue, further investigation of the above treatments, with particular attention paid to their mechanisms of action, the neurotransmitters involved and their effects on cortico-thalamocortical circuitry, is needed.

Functional isolation within the cerebral cortex in the vegetative state: A nonlinear method to predict clinical outcomes

Background. Establishing prognosis in patients in a persistent vegetative state (VS) is still challenging. Neural networks underlying consciousness may be regarded as complex systems whose outputs show a degree of unpredictability experimentally quantifiable by means of nonlinear parameters such as approximate entropy (ApEn). Objective. The authors propose that the VS might be the result of derangement of the above neural networks, with an ensuing decrease in complexity and mutual interconnectivity: this might lead to a functional isolation within the cerebral cortex and to a reduction in the chaotic behavior of its outputs, with monotony taking the place of unpredictability. To test this hypothesis, the authors investigated whether nonlinear dynamics methods applied to electroencephalography (EEG) recordings may be able to predict outcomes. Methods. A total of 38 vegetative patients and 40 matched healthy controls were investigated. At admission, all patients were assessed by means of the Extended Glasgow Outcomes Coma Scale (E-GOS) and the Coma Recovery Scale–Revised (CRS-R). At the same time an EEG recording was performed and used for time series analysis and ApEn computation. Patients were clinically reassessed at 6 months from the first evaluation. Results. Mean ApEn values (0.73, standard deviation [SD] = 0.12 vs 0.97, SD = 0.02; P < .001) were lower in patients than in controls. Patients with the lowest ApEn values either died (n = 14) or remained in a VS (n = 12), whereas patients with the highest ApEn values became minimally conscious (n = 5) or showed partial (n = 4) or full recovery (n = 3). Conclusions. These findings suggest that dynamic correlates of neural residual complexity might help in predicting outcomes in vegetative patients.

Peripheral vascular dysfunction in migraine: a review

Numerous studies have indicated an increased risk of vascular disease among migraineurs. Alterations in endothelial and arterial function, which predispose to atherosclerosis and cardiovascular diseases, have been suggested as an important link between migraine and vascular disease. However, the available evidence is inconsistent. We aimed to review and summarize the published evidence about the peripheral vascular dysfunction of migraineurs.We systematically searched in BIOSIS, the Cochrane database, Embase, Google scholar, ISI Web of Science, and Medline to identify articles, published up to April 2013, evaluating the endothelial and arterial function of migraineurs.Several lines of evidence for vascular dysfunction were reported in migraineurs. Findings regarding endothelial function are particularly controversial since studies variously indicated the presence of endothelial dysfunction in migraineurs, the absence of any difference in endothelial function between migraineurs and non-migraineurs, and even an enhanced endothelial function in migraineurs. Reports on arterial function are more consistent and suggest that functional properties of large arteries are altered in migraineurs.Peripheral vascular function, particularly arterial function, is a promising non-invasive indicator of the vascular health of subjects with migraine. However, further targeted research is needed to understand whether altered arterial function explains the increased risk of vascular disease among patients with migraine.

Migraine and risk of ischaemic heart disease: a systematic review and meta-analysis of observational studies

Several studies have assessed the risk of ischaemic heart diseases in migraineurs, drawing different conclusions. To define and update the issue, a systematic review and meta‐analysis of the available observational studies was performed.

Action observation improves motor imagery: specific interactions between simulative processes

In the present study, we demonstrated that observation of hand rotation had specific facilitation effects on a classical motor imagery task, the hand-laterality judgement. In Experiment 1, we found that action observation improved subjects’ performance on the hand laterality but not on the letter rotation task (stimulus specificity). In Experiment 2, we demonstrated that this facilitation was not due to mere observation of a moving hand, because it was triggered by observation of manual rotation but not of manual prehension movements (motion specificity). In Experiment 3, this stimulus- and motion-specific effect was found to be right hand-specific, compatible with left-hemispheric specialization in motor imagery but not in action observation. These data provided direct support to the idea that different simulation states, such as action observation and motor imagery, share some common mechanisms but also show specific functional differences.

Contribution of Hematocrit to Early Mortality after Ischemic Stroke

Background: Only a few non-recent studies assessed the importance of hematocrit (HCT) in patients with ischemic stroke. We evaluated how HCT might affect early mortality after stroke. Methods: We investigated all first-ever ischemic strokes included in the population-based L’Aquila registry. 3,481 patients according to HCT (%) values were included into four categories (≤40, 41–45, 46–50, and >50). Results: There were more men than women with HCT >50 (6.6 vs. 2.8%; p < 0.0001) and more women than men with HCT ≤40 (48.5 vs. 37.9%; p < 0.0001). Proportions of chronic atrial fibrillation (p = 0.0053) increased in women from the lower to the higher HCT categories. 7- and 28-day case-fatality rates were similar in men and women in the lower HCT categories but higher in women than in men in the higher categories. At the 28-day Kaplan-Meier analysis, men had similar survivals in the different categories while women with HCT >50 showed the worst survival (p < 0.0001). At the multivariate Cox regression analysis HCT 46–50 and >50 was an independent predictor of mortality in women within 28 days. Conclusion:High HCT might represent in women a previously underestimated independent predictor of mortality after ischemic stroke. Consideration of HCT in future stroke trials would be useful for ameliorating stroke care, especially in women.

Resting state eyes-closed cortical rhythms in patients with locked-in-syndrome: an EEG study

OBJECTIVE Locked-in syndrome (LIS) is a state of complete paralysis, except for ocular movements, which results from ventral brainstem lesions. Patients typically are fully conscious. Here we tested the hypothesis that electroencephalographic (EEG) rhythms are abnormal in LIS patients, possibly due to an impaired neural synchronization between brainstem and cerebral cortex. METHODS Resting state eyes-closed EEG data were recorded in 13 LIS subjects and 15 cognitively normal control subjects. With reference to the individual alpha frequency (IAF), the bands of interest were delta (IAF-8 to IAF-6Hz), theta (IAF-6 to IAF-4Hz), alpha 1 (IAF-4 to IAF-2Hz), alpha 2 (IAF-2 to IAFHz), and alpha 3 (IAF to IAF+2Hz). Furthermore, beta 1 (13-20Hz) and beta 2 (20-30Hz) bands were also considered. Cortical EEG sources were estimated by low-resolution electromagnetic tomography (LORETA). RESULTS The power of alpha 2 and alpha 3 sources in all regions was lower in patients with LIS compared to controls. The power of delta sources in central, parietal, occipital and temporal regions was higher in patients with LIS compared to controls. CONCLUSIONS These results suggest that cortical sources of resting state eyes-closed alpha and delta rhythms are abnormal in LIS patients. SIGNIFICANCE LIS is accompanied by a functional impairment of cortical neuronal synchronization mechanisms in the resting state condition.